[Core] Init windows after application obj has been constructed.
[Core] Let main windows know if they are primary.
[Core] Let Root WM Manager to know when it initializes.
[Core] Only make full bg windows if they are primary.
[Core] Move primary windows to their screens.
[Core] Check for work size area initially.
[Core] Don't restore position for primary windows in desktop mode.
[Core] Don't create tray icons for non-primary windows.
Merge branch 'master' of github.com:0xd34df00d/leechcraft